Emissions

Subterms

    More stories

    • 163 Shares169 Views

      in Environment

      AI pilot programs look to reduce energy use and emissions on MIT campus

      by

      Smart thermostats have changed the way many people heat and cool their homes by using machine learning to respond to occupancy patterns and preferences, resulting in a lower energy draw. This technology — which can collect and synthesize data — generally focuses on single-dwelling use, but what if this type of artificial intelligence could dynamically manage the heating and cooling of an entire campus? That’s the idea behind a cross-departmental effort working to reduce campus energy use through AI building controls that respond in real-time to internal and external factors. 

      Understanding the challenge

      Heating and cooling can be an energy challenge for campuses like MIT, where existing building management systems (BMS) can’t respond quickly to internal factors like occupancy fluctuations or external factors such as forecast weather or the carbon intensity of the grid. This results in using more energy than needed to heat and cool spaces, often to sub-optimal levels. By engaging AI, researchers have begun to establish a framework to understand and predict optimal temperature set points (the temperature at which a thermostat has been set to maintain) at the individual room level and take into consideration a host of factors, allowing the existing systems to heat and cool more efficiently, all without manual intervention. 

      “It’s not that different from what folks are doing in houses,” explains Les Norford, a professor of architecture at MIT, whose work in energy studies, controls, and ventilation connected him with the effort. “Except we have to think about things like how long a classroom may be used in a day, weather predictions, time needed to heat and cool a room, the effect of the heat from the sun coming in the window, and how the classroom next door might impact all of this.” These factors are at the crux of the research and pilots that Norford and a team are focused on. That team includes Jeremy Gregory, executive director of the MIT Climate and Sustainability Consortium; Audun Botterud, principal research scientist for the Laboratory for Information and Decision Systems; Steve Lanou, project manager in the MIT Office of Sustainability (MITOS); Fran Selvaggio, Department of Facilities Senior Building Management Systems engineer; and Daisy Green and You Lin, both postdocs.

      The group is organized around the call to action to “explore possibilities to employ artificial intelligence to reduce on-campus energy consumption” outlined in Fast Forward: MIT’s Climate Action Plan for the Decade, but efforts extend back to 2019. “As we work to decarbonize our campus, we’re exploring all avenues,” says Vice President for Campus Services and Stewardship Joe Higgins, who originally pitched the idea to students at the 2019 MIT Energy Hack. “To me, it was a great opportunity to utilize MIT expertise and see how we can apply it to our campus and share what we learn with the building industry.” Research into the concept kicked off at the event and continued with undergraduate and graduate student researchers running differential equations and managing pilots to test the bounds of the idea. Soon, Gregory, who is also a MITOS faculty fellow, joined the project and helped identify other individuals to join the team. “My role as a faculty fellow is to find opportunities to connect the research community at MIT with challenges MIT itself is facing — so this was a perfect fit for that,” Gregory says. 

      Early pilots of the project focused on testing thermostat set points in NW23, home to the Department of Facilities and Office of Campus Planning, but Norford quickly realized that classrooms provide many more variables to test, and the pilot was expanded to Building 66, a mixed-use building that is home to classrooms, offices, and lab spaces. “We shifted our attention to study classrooms in part because of their complexity, but also the sheer scale — there are hundreds of them on campus, so [they offer] more opportunities to gather data and determine parameters of what we are testing,” says Norford. 

      Developing the technology

      The work to develop smarter building controls starts with a physics-based model using differential equations to understand how objects can heat up or cool down, store heat, and how the heat may flow across a building façade. External data like weather, carbon intensity of the power grid, and classroom schedules are also inputs, with the AI responding to these conditions to deliver an optimal thermostat set point each hour — one that provides the best trade-off between the two objectives of thermal comfort of occupants and energy use. That set point then tells the existing BMS how much to heat up or cool down a space. Real-life testing follows, surveying building occupants about their comfort. Botterud, whose research focuses on the interactions between engineering, economics, and policy in electricity markets, works to ensure that the AI algorithms can then translate this learning into energy and carbon emission savings. 

      Currently the pilots are focused on six classrooms within Building 66, with the intent to move onto lab spaces before expanding to the entire building. “The goal here is energy savings, but that’s not something we can fully assess until we complete a whole building,” explains Norford. “We have to work classroom by classroom to gather the data, but are looking at a much bigger picture.” The research team used its data-driven simulations to estimate significant energy savings while maintaining thermal comfort in the six classrooms over two days, but further work is needed to implement the controls and measure savings across an entire year. 

      With significant savings estimated across individual classrooms, the energy savings derived from an entire building could be substantial, and AI can help meet that goal, explains Botterud: “This whole concept of scalability is really at the heart of what we are doing. We’re spending a lot of time in Building 66 to figure out how it works and hoping that these algorithms can be scaled up with much less effort to other rooms and buildings so solutions we are developing can make a big impact at MIT,” he says.

      Part of that big impact involves operational staff, like Selvaggio, who are essential in connecting the research to current operations and putting them into practice across campus. “Much of the BMS team’s work is done in the pilot stage for a project like this,” he says. “We were able to get these AI systems up and running with our existing BMS within a matter of weeks, allowing the pilots to get off the ground quickly.” Selvaggio says in preparation for the completion of the pilots, the BMS team has identified an additional 50 buildings on campus where the technology can easily be installed in the future to start energy savings. The BMS team also collaborates with the building automation company, Schneider Electric, that has implemented the new control algorithms in Building 66 classrooms and is ready to expand to new pilot locations. 

      Expanding impact

      The successful completion of these programs will also open the possibility for even greater energy savings — bringing MIT closer to its decarbonization goals. “Beyond just energy savings, we can eventually turn our campus buildings into a virtual energy network, where thousands of thermostats are aggregated and coordinated to function as a unified virtual entity,” explains Higgins. These types of energy networks can accelerate power sector decarbonization by decreasing the need for carbon-intensive power plants at peak times and allowing for more efficient power grid energy use.

      As pilots continue, they fulfill another call to action in Fast Forward — for campus to be a “test bed for change.” Says Gregory: “This project is a great example of using our campus as a test bed — it brings in cutting-edge research to apply to decarbonizing our own campus. It’s a great project for its specific focus, but also for serving as a model for how to utilize the campus as a living lab.” More

    • 125 Shares199 Views

      in Energy

      Jackson Jewett wants to design buildings that use less concrete

      by

      After three years leading biking tours through U.S. National Parks, Jackson Jewett decided it was time for a change.

      “It was a lot of fun, but I realized I missed buildings,” says Jewett. “I really wanted to be a part of that industry, learn more about it, and reconnect with my roots in the built environment.”

      Jewett grew up in California in what he describes as a “very creative household.”

      “I remember making very elaborate Halloween costumes with my parents, making fun dioramas for school projects, and building forts in the backyard, that kind of thing,” Jewett explains.

      Both of his parents have backgrounds in design; his mother studied art in college and his father is a practicing architect. From a young age, Jewett was interested in following in his father’s footsteps. But when he arrived at the University of California at Berkeley in the midst of the 2009 housing crash, it didn’t seem like the right time. Jewett graduated with a degree in cognitive science and a minor in history of architecture. And even as he led tours through Yellowstone, the Grand Canyon, and other parks, buildings were in the back of his mind.

      It wasn’t just the built environment that Jewett was missing. He also longed for the rigor and structure of an academic environment.

      Jewett arrived at MIT in 2017, initially only planning on completing the master’s program in civil and environmental engineering. It was then that he first met Josephine Carstensen, a newly hired lecturer in the department. Jewett was interested in Carstensen’s work on “topology optimization,” which uses algorithms to design structures that can achieve their performance requirements while using only a limited amount of material. He was particularly interested in applying this approach to concrete design, and he collaborated with Carstensen to help demonstrate its viability.

      After earning his master’s, Jewett spent a year and a half as a structural engineer in New York City. But when Carstensen was hired as a professor, she reached out to Jewett about joining her lab as a PhD student. He was ready for another change.

      Now in the third year of his PhD program, Jewett’s dissertation work builds upon his master’s thesis to further refine algorithms that can design building-scale concrete structures that use less material, which would help lower carbon emissions from the construction industry. It is estimated that the concrete industry alone is responsible for 8 percent of global carbon emissions, so any efforts to reduce that number could help in the fight against climate change.

      Implementing new ideas

      Topology optimization is a small field, with the bulk of the prior work being computational without any experimental verification. The work Jewett completed for his master’s thesis was just the start of a long learning process.

      “I do feel like I’m just getting to the part where I can start implementing my own ideas without as much support as I’ve needed in the past,” says Jewett. “In the last couple of months, I’ve been working on a reinforced concrete optimization algorithm that I hope will be the cornerstone of my thesis.”

      The process of fine-tuning a generative algorithm is slow going, particularly when tackling a multifaceted problem.

      “It can take days or usually weeks to take a step toward making it work as an entire integrated system,” says Jewett. “The days when that breakthrough happens and I can see the algorithm converging on a solution that makes sense — those are really exciting moments.”

      By harnessing computational power, Jewett is searching for materially efficient components that can be used to make up structures such as bridges or buildings. These are other constraints to consider as well, particularly ensuring that the cost of manufacturing isn’t too high. Having worked in the industry before starting the PhD program, Jewett has an eye toward doing work that can be feasibly implemented.

      Inspiring others

      When Jewett first visited MIT campus, he was drawn in by the collaborative environment of the institute and the students’ drive to learn. Now, he’s a part of that process as a teaching assistant and a supervisor in the Undergraduate Research Opportunities Program.  

      Working as a teaching assistant isn’t a requirement for Jewett’s program, but it’s been one of his favorite parts of his time at MIT.

      “The MIT undergrads are so gifted and just constantly impress me,” says Jewett. “Being able to teach, especially in the context of what MIT values is a lot of fun. And I learn, too. My coding practices have gotten so much better since working with undergrads here.”

      Jewett’s experiences have inspired him to pursue a career in academia after the completion of his program, which he expects to complete in the spring of 2025. But he’s making sure to take care of himself along the way. He still finds time to plan cycling trips with his friends and has gotten into running ever since moving to Boston. So far, he’s completed two marathons.

      “It’s so inspiring to be in a place where so many good ideas are just bouncing back and forth all over campus,” says Jewett. “And on most days, I remember that and it inspires me. But it’s also the case that academics is hard, PhD programs are hard, and MIT — there’s pressure being here, and sometimes that pressure can feel like it’s working against you.”

      Jewett is grateful for the mental health resources that MIT provides students. While he says it can be imperfect, it’s been a crucial part of his journey.

      “My PhD thesis will be done in 2025, but the work won’t be done. The time horizon of when these things need to be implemented is relatively short if we want to make an impact before global temperatures have already risen too high. My PhD research will be developing a framework for how that could be done with concrete construction, but I’d like to keep thinking about other materials and construction methods even after this project is finished.” More

    • 100 Shares129 Views

      in Environment

      Harnessing hydrogen’s potential to address long-haul trucking emissions

      by

      The transportation of goods forms the basis of today’s globally distributed supply chains, and long-haul trucking is a central and critical link in this complex system. To meet climate goals around the world, it is necessary to develop decarbonized solutions to replace diesel powertrains, but given trucking’s indispensable and vast role, these solutions must be both economically viable and practical to implement. While hydrogen-based options, as an alternative to diesel, have the potential to become a promising decarbonization strategy, hydrogen has significant limitations when it comes to delivery and refueling.These roadblocks, combined with hydrogen’s compelling decarbonization potential, are what motivated a team of MIT researchers led by William H. Green, the Hoyt Hottel Professor in Chemical Engineering, to explore a cost-effective way to transport and store hydrogen using liquid organic hydrogen carriers (LOHCs). The team is developing a disruptive technology that allows LOHCs to not only deliver the hydrogen to the trucks, but also store the hydrogen onboard.Their findings were recently published in Energy and Fuels, a peer-reviewed journal of the American Chemical Society, in a paper titled “Perspective on Decarbonizing Long-Haul Trucks Using Onboard Dehydrogenation of Liquid Organic Hydrogen Carriers.” The MIT team is led by Green, and includes graduate students Sayandeep Biswas and Kariana Moreno Sader. Their research is supported by the MIT Climate and Sustainability Consortium (MCSC) through its Seed Awards program and MathWorks, and ties into the work within the MCSC’s Tough Transportation Modes focus area.An “onboard” approachCurrently, LOHCs, which work within existing retail fuel distribution infrastructure, are used to deliver hydrogen gas to refueling stations, where it is then compressed and delivered onto trucks equipped with hydrogen fuel cell or combustion engines.“This current approach incurs significant energy loss due to endothermic hydrogen release and compression at the retail station” says Green. “To address this, our work is exploring a more efficient application, with LOHC-powered trucks featuring onboard dehydrogenation.”To implement such a design, the team aims to modify the truck’s powertrain (the system inside a vehicle that produces the energy to propel it forward) to allow onboard hydrogen release from the LOHCs, using waste heat from the engine exhaust to power the “dehydrogenation” process. 

      Proposed process flow diagram for onboard dehydrogenation. Component sizes are not to scale and have been enlarged for illustrative purposes.

      Image courtesy of the Green Group.

      Previous item
      Next item

      The dehydrogenation process happens within a high-temperature reactor, which continually receives hydrogen-rich LOHCs from the fuel storage tank. Hydrogen released from the reactor is fed to the engine, after passing through a separator to remove any lingering LOHC. On its way to the engine, some of the hydrogen gets diverted to a burner to heat the reactor, which helps to augment the reactor heating provided by the engine exhaust gases.Acknowledging and addressing hydrogen’s drawbacksThe team’s paper underscores that current uses of hydrogen, including LOHC systems, to decarbonize the trucking sector have drawbacks. Regardless of technical improvements, these existing options remain prohibitively expensive due to the high cost of retail hydrogen delivery.“We present an alternative option that addresses a lot of the challenges and seems to be a viable way in which hydrogen can be used in this transportation context,” says Biswas, who was recently elected to the MIT Martin Family Society of Fellows for Sustainability for his work in this area. “Hydrogen, when used through LOHCs, has clear benefits for long-hauling, such as scalability and fast refueling time. There is also an enormous potential to improve delivery and refueling to further reduce cost, and our system is working to do that.”“Utilizing hydrogen is an option that is globally accessible, and could be extended to countries like the one where I am from,” says Moreno Sader, who is originally from Colombia. “Since it synergizes with existing infrastructure, large upfront investments are not necessary. The global applicability is huge.”Moreno Sader is a MathWorks Fellow, and, along with the rest of the team, has been using MATLAB tools to develop models and simulations for this work.Different sectors coming togetherDecarbonizing transportation modes, including long-haul trucking, requires expertise and perspectives from different industries — an approach that resonates with the MCSC’s mission.The team’s groundbreaking research into LOHC-powered trucking is among several projects supported by the MCSC within its Tough Transportation Modes focus area, led by postdoc Impact Fellow Danika MacDonell. The MCSC-supported projects were chosen to tackle a complementary set of societally important and industry-relevant challenges to decarbonizing heavy-duty transportation, which span a range of sectors and solution pathways. Other projects focus, for example, on logistics optimization for electrified trucking fleets, or air quality and climate impacts of ammonia-powered shipping.The MCSC works to support and amplify the impact of these projects by engaging the research teams with industry partners from a variety of sectors. In addition, the MCSC pursues a collective multisectoral approach to decarbonizing transportation by facilitating shared learning across the different projects through regular cross-team discussion.The research led by Green celebrates this cross-sector theme by integrating industry-leading computing tools provided by MathWorks with cutting-edge developments in chemical engineering, as well as industry-leading commercial LOHC reactor demonstrations, to build a compelling vision for cost-effective LOHC-powered trucking.The review and research conducted in the Energy and Fuels article lays the groundwork for further investigations into LOHC-powered truck design. The development of such a vehicle — with a power-dense, efficient, and robust onboard hydrogen release system — requires dedicated investigations and further optimization of core components geared specifically toward the trucking application. More

    • 113 Shares189 Views

      in Energy

      Study suggests energy-efficient route to capturing and converting CO2

      by

      In the race to draw down greenhouse gas emissions around the world, scientists at MIT are looking to carbon-capture technologies to decarbonize the most stubborn industrial emitters.

      Steel, cement, and chemical manufacturing are especially difficult industries to decarbonize, as carbon and fossil fuels are inherent ingredients in their production. Technologies that can capture carbon emissions and convert them into forms that feed back into the production process could help to reduce the overall emissions from these “hard-to-abate” sectors.

      But thus far, experimental technologies that capture and convert carbon dioxide do so as two separate processes, that themselves require a huge amount of energy to run. The MIT team is looking to combine the two processes into one integrated and far more energy-efficient system that could potentially run on renewable energy to both capture and convert carbon dioxide from concentrated, industrial sources.

      In a study appearing today in ACS Catalysis, the researchers reveal the hidden functioning of how carbon dioxide can be both captured and converted through a single electrochemical process. The process involves using an electrode to attract carbon dioxide released from a sorbent, and to convert it into a reduced, reusable form.

      Others have reported similar demonstrations, but the mechanisms driving the electrochemical reaction have remained unclear. The MIT team carried out extensive experiments to determine that driver, and found that, in the end, it came down to the partial pressure of carbon dioxide. In other words, the more pure carbon dioxide that makes contact with the electrode, the more efficiently the electrode can capture and convert the molecule.

      Knowledge of this main driver, or “active species,” can help scientists tune and optimize similar electrochemical systems to efficiently capture and convert carbon dioxide in an integrated process.

      The study’s results imply that, while these electrochemical systems would probably not work for very dilute environments (for instance, to capture and convert carbon emissions directly from the air), they would be well-suited to the highly concentrated emissions generated by industrial processes, particularly those that have no obvious renewable alternative.

      “We can and should switch to renewables for electricity production. But deeply decarbonizing industries like cement or steel production is challenging and will take a longer time,” says study author Betar Gallant, the Class of 1922 Career Development Associate Professor at MIT. “Even if we get rid of all our power plants, we need some solutions to deal with the emissions from other industries in the shorter term, before we can fully decarbonize them. That’s where we see a sweet spot, where something like this system could fit.”

      The study’s MIT co-authors are lead author and postdoc Graham Leverick and graduate student Elizabeth Bernhardt, along with Aisyah Illyani Ismail, Jun Hui Law, Arif Arifutzzaman, and Mohamed Kheireddine Aroua of Sunway University in Malaysia.

      Breaking bonds

      Carbon-capture technologies are designed to capture emissions, or “flue gas,” from the smokestacks of power plants and manufacturing facilities. This is done primarily using large retrofits to funnel emissions into chambers filled with a “capture” solution — a mix of amines, or ammonia-based compounds, that chemically bind with carbon dioxide, producing a stable form that can be separated out from the rest of the flue gas.

      High temperatures are then applied, typically in the form of fossil-fuel-generated steam, to release the captured carbon dioxide from its amine bond. In its pure form, the gas can then be pumped into storage tanks or underground, mineralized, or further converted into chemicals or fuels.

      “Carbon capture is a mature technology, in that the chemistry has been known for about 100 years, but it requires really large installations, and is quite expensive and energy-intensive to run,” Gallant notes. “What we want are technologies that are more modular and flexible and can be adapted to more diverse sources of carbon dioxide. Electrochemical systems can help to address that.”

      Her group at MIT is developing an electrochemical system that both recovers the captured carbon dioxide and converts it into a reduced, usable product. Such an integrated system, rather than a decoupled one, she says, could be entirely powered with renewable electricity rather than fossil-fuel-derived steam.

      Their concept centers on an electrode that would fit into existing chambers of carbon-capture solutions. When a voltage is applied to the electrode, electrons flow onto the reactive form of carbon dioxide and convert it to a product using protons supplied from water. This makes the sorbent available to bind more carbon dioxide, rather than using steam to do the same.

      Gallant previously demonstrated this electrochemical process could work to capture and convert carbon dioxide into a solid carbonate form.

      “We showed that this electrochemical process was feasible in very early concepts,” she says. “Since then, there have been other studies focused on using this process to attempt to produce useful chemicals and fuels. But there’s been inconsistent explanations of how these reactions work, under the hood.”

      Solo CO2

      In the new study, the MIT team took a magnifying glass under the hood to tease out the specific reactions driving the electrochemical process. In the lab, they generated amine solutions that resemble the industrial capture solutions used to extract carbon dioxide from flue gas. They methodically altered various properties of each solution, such as the pH, concentration, and type of amine, then ran each solution past an electrode made from silver — a metal that is widely used in electrolysis studies and known to efficiently convert carbon dioxide to carbon monoxide. They then measured the concentration of carbon monoxide that was converted at the end of the reaction, and compared this number against that of every other solution they tested, to see which parameter had the most influence on how much carbon monoxide was produced.

      In the end, they found that what mattered most was not the type of amine used to initially capture carbon dioxide, as many have suspected. Instead, it was the concentration of solo, free-floating carbon dioxide molecules, which avoided bonding with amines but were nevertheless present in the solution. This “solo-CO2” determined the concentration of carbon monoxide that was ultimately produced.

      “We found that it’s easier to react this ‘solo’ CO2, as compared to CO2 that has been captured by the amine,” Leverick offers. “This tells future researchers that this process could be feasible for industrial streams, where high concentrations of carbon dioxide could efficiently be captured and converted into useful chemicals and fuels.”

      “This is not a removal technology, and it’s important to state that,” Gallant stresses. “The value that it does bring is that it allows us to recycle carbon dioxide some number of times while sustaining existing industrial processes, for fewer associated emissions. Ultimately, my dream is that electrochemical systems can be used to facilitate mineralization, and permanent storage of CO2 — a true removal technology. That’s a longer-term vision. And a lot of the science we’re starting to understand is a first step toward designing those processes.”

      This research is supported by Sunway University in Malaysia. More

    • 75 Shares99 Views

      in Environment

      Explained: The 1.5 C climate benchmark

      by

      The summer of 2023 has been a season of weather extremes.

      In June, uncontrolled wildfires ripped through parts of Canada, sending smoke into the U.S. and setting off air quality alerts in dozens of downwind states. In July, the world set the hottest global temperature on record, which it held for three days in a row, then broke again on day four.

      From July into August, unrelenting heat blanketed large parts of Europe, Asia, and the U.S., while India faced a torrential monsoon season, and heavy rains flooded regions in the northeastern U.S. And most recently, whipped up by high winds and dry vegetation, a historic wildfire tore through Maui, devastating an entire town.

      These extreme weather events are mainly a consequence of climate change driven by humans’ continued burning of coal, oil, and natural gas. Climate scientists agree that extreme weather such as what people experienced this summer will likely grow more frequent and intense in the coming years unless something is done, on a persistent and planet-wide scale, to rein in global temperatures.

      Just how much reining-in are they talking about? The number that is internationally agreed upon is 1.5 degrees Celsius. To prevent worsening and potentially irreversible effects of climate change, the world’s average temperature should not exceed that of preindustrial times by more than 1.5 degrees Celsius (2.7 degrees Fahrenheit).

      As more regions around the world face extreme weather, it’s worth taking stock of the 1.5-degree bar, where the planet stands in relation to this threshold, and what can be done at the global, regional, and personal level, to “keep 1.5 alive.”

      Why 1.5 C?

      In 2015, in response to the growing urgency of climate impacts, nearly every country in the world signed onto the Paris Agreement, a landmark international treaty under which 195 nations pledged to hold the Earth’s temperature to “well below 2 degrees Celsius above pre-industrial levels,” and going further, aim to “limit the temperature increase to 1.5 degrees Celsius above pre-industrial levels.”

      The treaty did not define a particular preindustrial period, though scientists generally consider the years from 1850 to 1900 to be a reliable reference; this time predates humans’ use of fossil fuels and is also the earliest period when global observations of land and sea temperatures are available. During this period, the average global temperature, while swinging up and down in certain years, generally hovered around 13.5 degrees Celsius, or 56.3 degrees Fahrenheit.

      The treaty was informed by a fact-finding report which concluded that, even global warming of 1.5 degrees Celsius above the preindustrial average, over an extended, decades-long period, would lead to high risks for “some regions and vulnerable ecosystems.” The recommendation then, was to set the 1.5 degrees Celsius limit as a “defense line” — if the world can keep below this line, it potentially could avoid the more extreme and irreversible climate effects that would occur with a 2 degrees Celsius increase, and for some places, an even smaller increase than that.

      But, as many regions are experiencing today, keeping below the 1.5 line is no guarantee of avoiding extreme, global warming effects.

      “There is nothing magical about the 1.5 number, other than that is an agreed aspirational target. Keeping at 1.4 is better than 1.5, and 1.3 is better than 1.4, and so on,” says Sergey Paltsev, deputy director of MIT’s Joint Program on the Science and Policy of Global Change. “The science does not tell us that if, for example, the temperature increase is 1.51 degrees Celsius, then it would definitely be the end of the world. Similarly, if the temperature would stay at 1.49 degrees increase, it does not mean that we will eliminate all impacts of climate change. What is known: The lower the target for an increase in temperature, the lower the risks of climate impacts.”

      How close are we to 1.5 C?

      In 2022, the average global temperature was about 1.15 degrees Celsius above preindustrial levels. According to the World Meteorological Organization (WMO), the cyclical weather phenomenon La Niña recently contributed to temporarily cooling and dampening the effects of human-induced climate change. La Niña lasted for three years and ended around March of 2023.

      In May, the WMO issued a report that projected a significant likelihood (66 percent) that the world would exceed the 1.5 degrees Celsius threshold in the next four years. This breach would likely be driven by human-induced climate change, combined with a warming El Niño — a cyclical weather phenomenon that temporarily heats up ocean regions and pushes global temperatures higher.

      This summer, an El Niño is currently underway, and the event typically raises global temperatures in the year after it sets in, which in this case would be in 2024. The WMO predicts that, for each of the next four years, the global average temperature is likely to swing between 1.1 and 1.8 degrees Celsius above preindustrial levels.

      Though there is a good chance the world will get hotter than the 1.5-degree limit as the result of El Niño, the breach would be temporary, and for now, would not have failed the Paris Agreement, which aims to keep global temperatures below the 1.5-degree limit over the long term (averaged over several decades rather than a single year).

      “But we should not forget that this is a global average, and there are variations regionally and seasonally,” says Elfatih Eltahir, the H.M. King Bhumibol Professor and Professor of Civil and Environmental Engineering at MIT. “This year, we had extreme conditions around the world, even though we haven’t reached the 1.5 C threshold. So, even if we control the average at a global magnitude, we are going to see events that are extreme, because of climate change.”

      More than a number

      To hold the planet’s long-term average temperature to below the 1.5-degree threshold, the world will have to reach net zero emissions by the year 2050, according to the Intergovernmental Panel on Climate Change (IPCC). This means that, in terms of the emissions released by the burning of coal, oil, and natural gas, the entire world will have to remove as much as it puts into the atmosphere.

      “In terms of innovations, we need all of them — even those that may seem quite exotic at this point: fusion, direct air capture, and others,” Paltsev says.

      The task of curbing emissions in time is particularly daunting for the United States, which generates the most carbon dioxide emissions of any other country in the world.

      “The U.S.’s burning of fossil fuels and consumption of energy is just way above the rest of the world. That’s a persistent problem,” Eltahir says. “And the national statistics are an aggregate of what a lot of individuals are doing.”

      At an individual level, there are things that can be done to help bring down one’s personal emissions, and potentially chip away at rising global temperatures.

      “We are consumers of products that either embody greenhouse gases, such as meat, clothes, computers, and homes, or we are directly responsible for emitting greenhouse gases, such as when we use cars, airplanes, electricity, and air conditioners,” Paltsev says. “Our everyday choices affect the amount of emissions that are added to the atmosphere.”

      But to compel people to change their emissions, it may be less about a number, and more about a feeling.

      “To get people to act, my hypothesis is, you need to reach them not just by convincing them to be good citizens and saying it’s good for the world to keep below 1.5 degrees, but showing how they individually will be impacted,” says Eltahir, who specializes on the study of regional climates, focusing on how climate change impacts the water cycle and frequency of extreme weather such as heat waves.

      “True climate progress requires a dramatic change in how the human system gets its energy,” Paltsev says. “It is a huge undertaking. Are you ready personally to make sacrifices and to change the way of your life? If one gets an honest answer to that question, it would help to understand why true climate progress is so difficult to achieve.” More

    • 163 Shares129 Views

      in Energy

      Q&A: Three Tata Fellows on the program’s impact on themselves and the world

      by

      The Tata Fellowship at MIT gives graduate students the opportunity to pursue interdisciplinary research and work with real-world applications in developing countries. Part of the MIT Tata Center for Technology and Design, this fellowship contributes to the center’s goal of designing appropriate, practical solutions for resource-constrained communities. Three Tata Fellows — Serena Patel, Rameen Hayat Malik, and Ethan Harrison — discuss the impact of this program on their research, perspectives, and time at MIT.

      Serena Patel

      Serena Patel graduated from the University of California at Berkeley with a degree in energy engineering and a minor in energy and resources. She is currently pursuing her SM in technology and policy at MIT and is a Tata Fellow focusing on decarbonization in India using techno-economic modeling. Her interest in the intersection of technology, policy, economics, and social justice led her to attend COP27, where she experienced decision-maker and activist interactions firsthand.

      Q: How did you become interested in the Tata Fellowship, and how has it influenced your time at MIT?

      A: The Tata Center appealed to my interest in searching for creative, sustainable energy technologies that center collaboration with local-leading organizations. It has also shaped my understanding of the role of technology in sustainable development planning. Our current energy system disproportionately impacts marginalized communities, and new energy systems have the potential to perpetuate and/or create inequities. I am broadly interested in how we can put people at the core of our technological solutions and support equitable energy transitions. I specifically work on techno-economic modeling to analyze the potential for an early retirement of India’s large coal fleet and conversion to long-duration thermal energy storage. This could mitigate job losses from rapid transitions, support India’s energy system decarbonization plan, and provide a cost-effective way to retire stranded assets.

      Q: Why is interdisciplinary study important to real-world solutions for global communities, and how has working at the intersection of technology and policy influenced your research?

      A: Technology and policy work together in mediating and regulating the world around us. Technological solutions can be disruptive in all the good ways, but they can also do a lot of harm and perpetuate existing inequities. Interdisciplinary studies are important to mitigate these interrelated issues so innovative ideas in the ivory towers of Western academia do not negatively impact marginalized communities. For real-world solutions to positively impact individuals, marginalized communities need to be centered within the research design process. I think the research community’s perspective on real-world, global solutions is shifting to achieve these goals, but much work remains for resources to reach the right communities.

      The energy space is especially fascinating because it impacts everyone’s quality of life in overt or nuanced ways. I’ve had the privilege of taking classes that sit at the intersection of energy technology and policy, involving land-use law, geographic representation, energy regulation, and technology policy. In general, working at the intersection of technology and policy has shaped my perspective on how regulation influences widespread technology adoption and the overall research directions and assumptions in our energy models.

      Q: How has your experience at COP27 influenced your approach to your research?

      A: Attending COP27 at Sharm El-Sheikh, Egypt, last November influenced my understanding of the role of science, research, and activism in climate negotiations and action. Science and research are often promoted as necessary for sharing knowledge at the higher levels, but they were also used as a delay tactic by negotiators. I heard how institutional bodies meant to support fair science and research often did not reach intended stakeholders. Lofty goals or financial commitments to ensure global climate stability and resilience still lacked implementation and coordination with deep technology transfer and support. On the face of it, these agreements have impact and influence, but I heard many frustrations over the lack of tangible, local support. This has driven my research to be as context-specific as possible, to provide actionable insights and leverage different disciplines.

      I also observed the role of activism in the negotiations. Decision-makers are accountable to their country, and activists are spreading awareness and bringing transparency to the COP process. As a U.S. citizen, I suddenly became more aware of how political engagement and awareness in the country could push the boundaries of international climate agreements if the government were more aligned on climate action.

      Rameen Hayat Malik

      Rameen Hayat Malik graduated from the University of Sydney with a bachelor’s degree in chemical and biomolecular engineering and a Bachelor of Laws. She is currently pursuing her SM in technology and policy and is a Tata Fellow researching the impacts of electric vehicle (EV) battery production in Indonesia. Originally from Australia, she first became interested in the geopolitical landscape of resources trade and its implications for the clean energy transition while working in her native country’s Department of Climate Change, Energy, the Environment and Water.

      Q: How did you become interested in the Tata Fellowship, and how has it influenced your time at MIT?

      A: I came across the Tata Fellowship while looking for research opportunities that aligned with my interest in understanding how a just energy transition will occur in a global context, with a particular focus on emerging economies. My research explores the techno-economic, social, and environmental impacts of nickel mining in Indonesia as it seeks to establish itself as a major producer of EV batteries. The fellowship’s focus on community-driven research has given me the freedom to guide the scope of my research. It has allowed me to integrate a community voice into my work that seeks to understand the impact of this mining on forest-dependent communities, Indigenous communities, and workforce development.

      Q: Battery technology and production are highly discussed in the energy sector. How does your research on Indonesia’s battery production contribute to the current discussion around batteries, and what drew you to this topic?

      A: Indonesia is one of the world’s largest exporters of coal, while also having one of the largest nickel reserves in the world — a key mineral for EV battery production. This presents an exciting opportunity for Indonesia to be a leader in the energy transition, as it both seeks to phase out coal production and establish itself as a key supplier of critical minerals. It is also an opportunity to actually apply principles of a just transition to the region, which seeks to repurpose and re-skill existing coal workforces, to bring Indigenous communities into the conversation around the future of their lands, and to explore whether it is actually possible to sustainably and ethically produce nickel for EV battery production.

      I’ve always seen battery technologies and EVs as products that, at least today, are accessible to a small, privileged customer base that can afford such technologies. I’m interested in understanding how we can make such products more widely affordable and provide our lowest-income communities with the opportunities to actively participate in the transition — especially since access to transportation is a key driver of social mobility. With nickel prices impacting EV prices in such a dramatic way, unlocking more nickel supply chains presents an opportunity to make EV batteries more accessible and affordable.

      Q: What advice would you give to new students who want to be a part of real-world solutions to the climate crisis?

      A: Bring your whole self with you when engaging these issues. Quite often we get caught up with the technology or modeling aspect of addressing the climate crisis and forget to bring people and their experiences into our work. Think about your positionality: Who is your community, what are the avenues you have to bring that community along, and what privileges do you hold to empower and amplify voices that need to be heard? Find a piece of this complex puzzle that excites you, and find opportunities to talk and listen to people who are directly impacted by the solutions you are looking to explore. It can get quite overwhelming working in this space, which carries a sense of urgency, politicization, and polarization with it. Stay optimistic, keep advocating, and remember to take care of yourself while doing this important work.

      Ethan Harrison

      After earning his degree in economics and applied science from the College of William and Mary, Ethan Harrison worked at the United Nations Development Program in its Crisis Bureau as a research officer focused on conflict prevention and predictive analysis. He is currently pursuing his SM in technology and policy at MIT. In his Tata Fellowship, he focuses on the impacts of the Ukraine-Russia conflict on global vulnerability and the global energy market.

      Q: How did you become interested in the Tata Fellowship, and how has it influenced your time at MIT?

      A: Coming to MIT, one of my chief interests was figuring out how we can leverage gains from technology to improve outcomes and build pro-poor solutions in developing and crisis contexts. The Tata Fellowship aligned with many of the conclusions I drew while working in crisis contexts and some of the outstanding questions that I was hoping to answer during my time at MIT, specifically: How can we leverage technology to build sustainable, participatory, and ethically grounded interventions in these contexts?

      My research currently examines the secondary impacts of the Ukraine-Russia conflict on low- and middle-income countries — especially fragile states — with a focus on shocks in the global energy market. This includes the development of a novel framework that systematically identifies factors of vulnerability — such as in energy, food systems, and trade dependence — and quantitatively ranks countries by their level of vulnerability. By identifying the specific mechanisms by which these countries are vulnerable, we can develop a map of global vulnerability and identify key policy solutions that can insulate countries from current and future shocks.

      Q: I understand that your research deals with the relationship between oil and gas price fluctuation and political stability. What has been the most surprising aspect of this relationship, and what are its implications for global decarbonization?

      A: One surprising aspect is the degree to which citizen grievances regarding price fluctuations can quickly expand to broader democratic demands and destabilization. In Sri Lanka last year and in Egypt during the Arab spring, initial protests around fuel prices and power outages eventually led to broader demands and the loss of power by heads of state. Another surprising aspect is the popularity of fuel subsidies despite the fact that they are economically regressive: They often comprise a large proportion of GDP in poor countries, disproportionately benefit higher-income populations, and leave countries vulnerable to fiscal stress during price spikes.

      Regarding implications for global decarbonization, one project we are pursuing examines the implications of directing financing from fuel subsidies toward investments in renewable energy. Countries that rely on fossil fuels for electricity have been hit especially hard 
by price spikes from the Ukraine-Russia conflict, especially since many were carrying costly fuel subsidies to keep the price of fuel and energy artificially low. Much of the international community is advocating for low-income countries to invest in renewables and reduce their fossil fuel burden, but it’s important to explore how global decarbonization can align with efforts to end energy poverty and other Sustainable Development Goals.

      Q: How does your research impact the Tata Center’s goal of transforming policy research into real-world solutions, and why is this important?

      A: The crisis in Ukraine has shifted the international community’s focus away from other countries in crisis, such as Yemen and Lebanon. By developing a global map of vulnerability, we’re building a large evidence base on which countries have been most impacted by this crisis. Most importantly, by identifying individual channels of vulnerability for each country, we can also identify the most effective policy solutions to insulate vulnerable populations from shocks. Whether that’s advocating for short-term social protection programs or identifying more medium-term policy solutions — like fuel banks or investment in renewables — we hope providing a detailed map of sources of vulnerability can help inform the global response to shocks imposed by the Russia-Ukraine conflict and post-Covid recovery. More

    • 88 Shares99 Views

      in Energy

      Bringing sustainable and affordable electricity to all

      by

      When MIT electrical engineer Reja Amatya PhD ’12 arrived in Rwanda in 2015, she was whisked off to a village. She saw that diesel generators provided power to the local health center, bank, and shops, but like most of rural Rwanda, Karambi’s 200 homes did not have electricity. Amatya knew the hilly terrain would make it challenging to connect the village to high-voltage lines from the capital, Kigali, 50 kilometers away.

      While many consider electricity a basic human right, there are places where people have never flipped a light switch. Among the United Nations’ Sustainable Development Goals is global access to affordable, reliable, and sustainable energy by 2030. Recently, the U.N. reported that progress in global electrification had slowed due to the challenge of reaching those hardest to reach.

      Researchers from the MIT Energy Initiative (MITEI) and Comillas Pontifical University in Madrid created Waya Energy Inc., a Cambridge, Massachusetts-based startup commercializing MIT-developed planning and analysis software, to help governments determine the most cost-effective ways to provide electricity to all their citizens.

      The researchers’ 2015 trip to Rwanda marked the beginning of four years of phone calls, Zoom meetings, and international travel to help the east African country — still reeling from the 1994 genocide that killed more than a million people — develop a national electrification strategy and extend its power infrastructure.

      Amatya, Waya president and one of five Waya co-founders, knew that electrifying Karambi and the rest of the country would provide new opportunities for work, education, and connections — and the ability to charge cellphones, often an expensive and inconvenient undertaking.

      To date, Waya — with funding from the Asian Development Bank, the African Development Bank, the Inter-American Development Bank for Latin America, and the World Bank — has helped governments develop electrification plans in 22 countries on almost every continent, including in refugee camps in sub-Saharan Africa’s Sahel and Chad regions, where violence has led to 3 million internally displaced people.

      “With a modeling and visualization tool like ours, we are able to look at the entire spectrum of need and demand and say, ‘OK, what might be the most optimized solution?’” Amatya says.

      More than 15 graduate students and researchers from MIT and Comillas contributed to the development of Waya’s software under the supervision of Robert Stoner, the interim director at MITEI, and Ignacio Pérez-Arriaga, a visiting professor at the MIT Sloan School of Management from Comillas. Pérez-Arriaga looks at how changing electricity use patterns have forced utilities worldwide to rethink antiquated business models.

      The team’s Reference Electrification Model (REM) software pulls information from population density maps, satellite images, infrastructure data, and geospatial points of interest to determine where extending the grid will be most cost-effective and where other solutions would be more practical.

      “I always say we are agnostic to the technology,” Amatya says. “Traditionally, the only way to provide long-term reliable access was through the grid, but that’s changing. In many developing countries, there are many more challenges for utilities to provide reliable service.”

      Off-grid solutions

      Waya co-founder Stoner, who is also the founding director of the MIT Tata Center for Technology and Design, recognized early on that connecting homes to existing infrastructure was not always economically feasible. What’s more, billions of people with grid connections had unreliable access due to uneven regulation and challenging terrain.

      With Waya co-founders Andres Gonzalez-Garcia, a MITEI affiliate researcher, and Professor Fernando de Cuadra Garcia of Comillas, Pérez-Arriaga and Stoner led a team that developed a set of principles to guide universal regional electrification. Their approach — which they dubbed the Integrated Distribution Framework — incorporates elements of optimal planning as well as novel business models and regulation. Getting all three right is “necessary,” Stoner says, “if you want a viable long-term outcome.”

      Amatya says, “Initially, we designed REM to understand what the level of demand is in these countries with very rural and poor populations, and what the system should look like to serve it. We took a lot of that input into developing the model.” In 2019, Waya was created to commercialize the software and add consulting to the package of services the team provides.

      Now, in addition to advising governments and regulators on how to expand existing grids, Waya proposes options such as a mini-grid, powered by renewables like wind, hydropower, or solar, to serve single villages or large-scale mini-grid solutions for larger areas. In some cases, an even more localized, scalable solution is a mesh grid, which might consist of a single solar panel for a few houses that, over time, can be expanded and ultimately connected to the main grid.

      The REM software has been used to design off-grid systems for remote and mountainous regions in Uganda, Peru, Nigeria, Cambodia, Indonesia, India, and elsewhere. When Tata Power, India’s largest integrated power company, saw how well mini-grids would serve parts of east India, the company created a mini-grid division called Tata Renewables.

      Amatya notes that the REM software enables her to come up with an entire national electrification plan from her workspace in Cambridge. But site visits and on-the-ground partners are critical in helping the Waya team understand existing systems, engage with clients to assess demand, and identify stakeholders. In Haiti, an energy consultant reported that the existing grid had typically been operational only six out of every 24 hours. In Karambi, University of Rwanda students surveyed the village’s 200 families and helped lead a community-wide meeting.

      Waya connects with on-the-ground experts and agencies “who can engage directly with the government and other stakeholders, because many times those are the doors that we knock on,” Amatya says. “Local energy ministries, utilities, and regulators have to be open to regulatory change. They have to be open to working with financial institutions and new technology.”

      The goals of regulators, energy providers, funding agencies, and government officials must align in real time “to provide reliable access to energy for a billion people,” she says.

      Moving past challenges

      Growing up in Kathmandu, Amatya used to travel to remote villages with her father, an electrical engineer who designed cable systems for landlines for Nepal Telecom. She remembers being fascinated by the high-voltage lines crisscrossing Nepal on these trips. Now, she points out utility poles to her children and explains how the distribution lines carry power from local substations to customers.

      After majoring in engineering science and physics at Smith College, Amatya completed her PhD in electrical engineering at MIT in 2012. Within two years, she was traveling to off-grid communities in India as a research scientist exploring potential technologies for providing access. There were unexpected challenges: At the time, digitized geospatial data didn’t exist for many regions. In India in 2013, the team used phones to take pictures of paper maps spread out on tables. Team members now scour digital data available through Facebook, Google, Microsoft, and other sources for useful geographical information. 

      It’s one thing to create a plan, Amatya says, but how it gets utilized and implemented becomes a big question. With all the players involved — funding agencies, elected officials, utilities, private companies, and regulators within the countries themselves — it’s sometimes hard to know who’s responsible for next steps.

      “Besides providing technical expertise, our team engages with governments to, let’s say, develop a financial plan or an implementation plan,” she says. Ideally, Waya hopes to stay involved with each project long enough to ensure that its proposal becomes the national electrification strategy of the country. That’s no small feat, given the multiple players, the opaque nature of government, and the need to enact a regulatory framework where none may have existed.

      For Rwanda, Waya identified areas without service, estimated future demand, and proposed the most cost-effective ways to meet that demand with a mix of grid and off-grid solutions. Based on the electrification plan developed by the Waya team, officials have said they hope to have the entire country electrified by 2024.

      In 2017, by the time the team submitted its master plan, which included an off-grid solution for Karambi, Amatya was surprised to learn that electrification in the village had already occurred — an example, she says, of the challenging nature of local planning.

      Perhaps because of Waya’s focus and outreach efforts, Karambi had become a priority. However it happened, Amatya is happy that Karambi’s 200 families finally have access to electricity. More

    • 150 Shares159 Views

      in Environment

      3 Questions: Boosting concrete’s ability to serve as a natural “carbon sink”

      by

      Damian Stefaniuk is a postdoc at the MIT Concrete Sustainability Hub (CSHub). He works with MIT professors Franz-Josef Ulm and Admir Masic of the MIT Department of Civil and Environmental Engineering (CEE) to investigate multifunctional concrete. Here, he provides an overview of carbonation in cement-based products, a brief explanation of why understanding carbonation in the life cycle of cement products is key for assessing their environmental impact, and an update on current research to bolster the process.

      Q: What is carbonation and why is it important for thinking about concrete from a life-cycle perspective?

      A: Carbonation is the reaction between carbon dioxide (CO2) and certain compounds in cement-based products, occurring during their use phase and end of life. It forms calcium carbonate (CaCO3) and has important implications for neutralizing the GHG [greenhouse gas] emissions and achieving carbon neutrality in the life cycle of concrete.

      Firstly, carbonation causes cement-based products to act as natural carbon sinks, sequestering CO2 from the air and storing it permanently. This helps mitigate the carbon emissions associated with the production of cement, reducing their overall carbon footprint.

      Secondly, carbonation affects concrete properties. Early-stage carbonation may increase the compressive strength of cement-based products, enhancing their durability and structural performance. However, late-stage carbonation can impact corrosion resistance in steel-reinforced concrete due to reduced alkalinity.

      Considering carbonation in the life cycle of cement-based products is crucial for accurately assessing their environmental impact. Understanding and leveraging carbonation can help industry reduce carbon emissions and maximize carbon sequestration potential. Paying close attention to it in the design process aids in creating durable and corrosion-resistant structures, contributing to longevity and overall sustainability.

      Q: What are some ongoing global efforts to force carbonation?

      A: Some ongoing efforts to force carbonation in concrete involve artificially increasing the amount of CO2 gas present during the early-stage hydration of concrete. This process, known as forced carbonation, aims to accelerate the carbonation reaction and its associated benefits.

      Forced carbonation is typically applied to precast concrete elements that are produced in artificially CO2-rich environments. By exposing fresh concrete to higher concentrations of CO2 during curing, the carbonation process can be expedited, resulting in potential improvements in strength, reduced water absorption, improved resistance to chloride permeability, and improved performance during freeze-thaw. At the same time, it can be difficult to quantify how much CO2 is absorbed and released because of the process.

      These efforts to induce early-stage carbonation through forced carbonation represent the industry’s focus on optimizing concrete performance and environmental impacts. By exploring methods to enhance the carbonation process, researchers and practitioners seek to more efficiently harness its benefits, such as increasing strength and sequestering CO2.

      It is important to note that forced carbonation requires careful implementation and monitoring to ensure desired outcomes. The specific procedures and conditions vary based on the application and intended goals, highlighting the need for expertise and controlled environments.

      Overall, ongoing efforts in forced carbonation contribute to the continuous development of concrete technology, aiming to improve its properties and reduce its carbon footprint throughout the life cycle of the material.

      Q: What is chemically-induced pre-cure carbonation, and what implications does it have?

      A: Chemically-induced pre-cure carbonation (CIPCC) is a method developed by the MIT CSHub to mineralize and permanently store CO2 in cement. Unlike traditional forced carbonation methods, CIPCC introduces CO2 into the concrete mix as a solid powder, specifically sodium bicarbonate. This approach addresses some of the limitations of current carbon capture and utilization technologies.

      The implications of CIPCC are significant. Firstly, it offers convenience for cast-in-place applications, making it easier to incorporate CO2 use in concrete projects. Unlike some other approaches, CIPCC allows for precise control over the quantity of CO2 sequestered in the concrete. This ensures accurate carbonation and facilitates better management of the storage process. CIPCC also builds on previous research regarding amorphous hydration phases, providing an additional mechanism for CO2 sequestration in cement-based products. These phases carbonate through CIPCC, contributing to the overall carbon sequestration capacity of the material.

      Furthermore, early-stage pre-cure carbonation shows promise as a pathway for concrete to permanently sequester a controlled and precise quantity of CO2. Our recent paper in PNAS Nexus suggests that it could theoretically offset at least 40 percent of the calcination emissions associated with cement production, when anticipating advances in the lower-emissions production of sodium bicarbonate. We also found that up to 15 percent of cement (by weight) could be substituted with sodium bicarbonate without compromising the mechanical performance of a given mix. Further research is needed to evaluate long-term effects of this process to explore the potential life-cycle savings and impacts of carbonation.

      CIPCC offers not only environmental benefits by reducing carbon emissions, but also practical advantages. The early-stage strength increase observed in real-world applications could expedite construction timelines by allowing concrete to reach its full strength faster.

      Overall, CIPCC demonstrates the potential for more efficient and controlled CO2 sequestration in concrete. It represents an important development in concrete sustainability, emphasizing the need for further research and considering the material’s life-cycle impacts.

      This research was carried out by MIT CSHub, which is sponsored by the Concrete Advancement Foundation and the Portland Cement Association. More